Underreamer.



C. T. MAPBS.

UNDERREAMBR. APPLICATION FILED JAN". 28, 1908.

Patented Nov. 17, 1908.

2 SHEETS-SHEET 2.

In k UNITED sTATEs PATENT oEEIcE.

CLARENCE T. IMAPES, OF GRAFTON, PENNSYLVANIA.

UNDERREAMIER.

\ Specification of Letters Patent.

Patented Nov. 17, 1908.

Application filed. ilannaryv28, 1908. Serial No. 413,013.

Toall rwhom it may concern: y

Be it known that I, CLARENCE T. MArEs, -a

citizen of the UnitedV States of America, re`

1o This invention relates to underreamers,

for reaming out or enlarging well-holes, and

particularly to such devices intended for underreaming-that is, reaming out or enlarging the well-hole drilled below a casing,

in order to permit the casing toI be lowered .farther down. i

The objectof my invention is to provide a simple, inexpensive and durable under reamer that can be successfully oper-ated in 2O Dthe most indurate strata of an oil field.

There are certain localities in this and foreign countries, where the operation of drilllng oil, gas lor Artesian wells is carried on, where broken and cavey strata of .rock must .bedrilled'g'througln and these formations are .,encountered at various depths. When Vsuch al formation is reached in the usual method of drilling, further attempt to drill the hole f deeper in the usual Way is useless, due to V`the caving in of rock and other substahces around the drilling tools, lthus retarding the actionsofsaid tools. A line .of screwed casing or pipe must then be. put into the well -to ai'ord protection for the tools in the fur- ''ther veil'ort to complete the well to .the required depth; this can only be accomplished by thealternate use of the drilling tools'and 'an underreamer operating through said line v of casing or pipe.

' 401 An underreamer comprises a body, adapted to bevattached tothe drill stem, and oarvrying oneV or more bits or dogs having cutting edges, said bits or dogs adapted to be compressed to the nominal diameter of the reamer-body and to automatically expand as they are passedA downthroughv and out of the bottom section of the line of casing or pipe and present a cutting surface of sufficient diameter to ,permit of the casing being lowered as the operation of underreaming proceeds.

My invention' aims to provide an underreamer wherein positive and reliable means are employed for effecting a movement of the dogs or rcamer heads, and bracing and firmly holding said" dogs or remuer lheuds while the underreamer is inoperation. To

this end I have devised an underreamer having laterally moving dogs or reamer cutters which are placed in an operative position by a spreader head or wedge block moved between said dogs or reamer heads, this spreader head firmly bracingvthe dogs and receiving any strain to which the dogs may be subjected when reaming.

Further, I aim to provide an underreamer consisting of comparatively4 few parts that can be easily and quickly assembled, easily lmanipulated to enter a well casing and easily disassembled when the dogs or reamer headsneed sharpening. Parts of the underreamer are arranged whereby they will be protected while passing through a well .casing, andare of such construction as to be easily renewed when completelyworn.

My invention will be presently described in detail and then specically-pointed out in the appended claims.

lIn the drawings: Figure l is a front elevation of my reamer illustrating the springcase thereof in section and the reamer m position to enter the casing of a well, Fig. 2 is a side elevation of the reamer, illustrating the dogs thereof in an operative position, Fig. 3 is a horizontal sectional view taken on the` line of Fig. l, Fig. 4 is a similar View taken on thc line of Fig. 2, Fig.

4 is a bottom plan'view of the spreader head' detached. Fig. 4b is a vertical sectional Viewv of a part of the spreader head'showing in dotted linesaportion of the dogs orreamer-4 bits in extended position. Fig. 4c is a de.

tached perspective view of the resilient strip' carried by the spreader head for normally retaining the dogs or reamer-bits in engage'- F ig. 5 is a longitudinal ment therewith.

sectional vie'w of a reamer taken Vonthe line a-a of Fig. 2, Fig. 6 is a front elevation of a reamer, partly in section, illustrating the reamer as .shown in Fig. 1 in position to enter the casing of a well, Fig. 7 is a similar view of a reamer, illustrating the manner of placing the dogs in position to enter the caslng of a well, Fig. 8 is a side elevation ofthe spreader head or wedge block-used 1n connection with the underreamer, Fig. 9 is a front elevationof the same, Fig. 1() is a side v elevation of vone of the dogs of the under- -reamer, Fig. 11 is a plan of the same, and

Fig. 12 isa front elevation ofthe dog.

To put my invention into practice, I pro' vide a remuer-body l, having at its upper end a screw joint 2 for a sub or spring-case 3, said spring-case having a central longitu-i dinal bore 4. This sub or spring-case is p rovided at its upper end with a screw joint, (not shown) similar to the screw joint 2, and in conjunction with the reamer-body is used in connection with a drill stem or jars (not shown), thus constituting part of the string of oil and Artesian well drilling tools. The reamer-body 1 is cylindrical and contiguous to the screw joint 2 is'provided with oppositely disposed fiat faces 5, adapted to receive a wrench, (not shown) commonly in use to tighten and loosen the screw joint 2.

Longitudinally of the reamer-body 1 a bore 6 i's formed, the lower end of said bore terminating in a cylindrical recess 7, for the reception of a spreader head or wedge block 8, detachably mounted upon the lower end ol a rod 9, that extends upwardly through the bore 6 into the bore 4 of the spring-case 3. Thenpper end-of the rod 9 is provided with a nut 10, and encirclin said rod 9, within the'bore 4,V are two coi springs 11 and 12, with an interposed washer 13 between said springs. The proclivity of these springs is to normally maintain the spreader head or wedge block 8 within the recess 7 of a reamer-body, and I use two springs instead. .of one, due to the fact that greater resiliency and a longer period .of use can be obtained from two springs than from one long spring.

The lower end of the reamer-body is provided with two alining dove-tail grooves 14 for the dove-tail tongues 15, carried by the upper flat ends of two oppositely disposed dogs, that are laterally moved and maintained in an extended position through the medium of the spring actuated spreader head or wedge block 8. The confronting faces of the. dogs are tapered, as at 16 and provided with dove-.tail ton es 17, these ton ues being approximately half the length of t e tapered faces of said dogs. The confronting faces of the dogs are also provided with` central semicylindrical grooves 18 cutting away a portion of the ta ered faces and the tongues 17 of said dogs. The

' grooves 18 provide a central opening to clear the rod 9, when said dogs are retracted or drawn towards one another in the grooves 14.

. The outer faces of the dogs are rounded as at 19 with the upper end thereof beveled, as at 20; the sides of said dogs are flattened, as at 21, and the lower ends of the dogs are beveled,vas at 23, to rovide cutting edges and clearance for the ogs when operating in a well.

The spreader head or wedge block 8 is of a peculiar shape,-appearing in side elevation as a cone, and in front elevation as an inverted T. The spreader head has its sides beveled as at 24, and provided .With-dovetail grooves 25 tol receive the dove tail tongues 17 of the dogs, thus establishing an adjustable connection between said dogs or bits and spreader head. In addition to the dove tail grooves 25 on the sides of the spreader head, the latter is provided on the bottom with a transversely-extending dovetail groove 26 which communicates or intersects at its ends with the lower ends of grooves 25. This groove 26 receives a plate, spring or resilient strip 27 of a length substantially equal to the length of tliegroove 2G, so that the end portions of said strip normally close the lower ends of the grooves 25 as shown in Fig. `5, and the strip is in engagement with the lower ends of the tongues 17. The said strip is provided intermediate its ends with dovetail tongues 6a which holdthe strip in the groove 26, the strip being thus held only at its central portion, so that the endl portions thereof may be depressed as the spreader head is drawn upwardly, as clearly illustrated in Fig. 4". This plate spring or resilient strip 27 is employed for normally holding the dogs in engagement with the reamer-body 1 and prevent any loose vertical movement of the dogs with relation to the reamer-body, which might be incurred by the tongues 15 wearing within the grooves 14. This plate spring or resilient strip forms an important factor of my invention, as it prevents pounding of the dogs, when the underreamer is in operation. The dogs are limited in their inward movement by contacting, as shown in Fig. 3 of the drawings.

By reason of the plate or resilient strip 27 being secured to the. spreader block only at the central portion of such plate or strip, and the ends thereof being therefore free to be depressed, it will be .observed that should any wear of the ton ues 15 occur, which is extremely likely, owingvto the rough usage to which devices of this nature are -subjected, that all lost motion that would other- -wise be occasioned due to such wear, willl be taken up by reason of the ends of the plate or ,strip 27 pressing upwardly against the dogs or bits. The object of securing the plate or strip 27 at the center only and thus leaving the ends thereof free to be depressed,i is to prevent the strip or plate from acting as a positive stop to further upward movement of the spreader block 8. If the strip were held at its ends as well as at the center thereof, it will be-observed that as soon as the v gagement with the lower ends ofthe tongues 17 of the dogs or bits, are pressing upwandly on the latter, and are thus effectively hold- `ing the latter to prevent any lostmotion between'the tongues 15 of the dogs or bits and the groove 14 in the body V1 that receives said tongues 15. The spreader head is provided with a central bore 28 terminating in a. threaded socket 29 adapted to receive the threaded end 30 of the rod 9. The curved lower sides 31 lof the spreader headrhave their bottom edges beveled, as at 31a, whereby the spreader'head will easily enter the upper end of the casing, as will hereinafter appear. y

The reamer-body is formed with diametrically opposed recesses 35, said recesses being formed lin the sides of the reamer-body that are at right angles tothe sides having the grooves 14 formed therein. The recesses 35 are formed with beveled shoulders 36, and adapted to normally lie in said recesses are diametrically opposed resilient arms or trip bars 37, having their lower ends reduced, asat 38, to .loosely tit in sockets 39 provided therefor in the spreader head 8. The upper ends-of the resilient arms or trip bars 37 are -provided with enlargements 40 adapted to 'protrude from the sides of the reamer-body, when the dogs are expanded or in an operative position, but lie Hush with the reamer-body when the dogsare retracted and the spreader head lowered between said dogs.

In order to insert the underreamer or tool in the casing of a well the dogs are drawn inwardlyby virtue of the vertical movement of the spreader head or wedge` block having dove-tail 'shaped grooves to' receive the tongues of said dogs. To pull the spreader head 8 downwardly, I use two hook-shaped members 33, loosely connected to the derrickV floor, as at 34. These hook-shaped members are adapted to engage in angularly disposed recesses 32. provided therefor in .the curved lower sides 31 of the spreader head. These hook-shaped members 33 are employed for holding the spreader head 8, while the reamer-body is elevated'to place the springs l11 and '12 under tension. When the spreader head 8 is pulled downwardly by usingpthe hook-shaped members 33, the resilient varms or trip bars 37` are carried downwardly in the recesses 35 until the upper ends of said arms engage the shoulders 36, this movement being limited by the dogs contacting, as shown in Fig. 3. Itis now necessary totemporarily hold the spreader head in this posi-V tion, due to the springs 11 and12 being compressed and under tension. this, I use a ring 41, which is split or made o en at one side, as shown in Figs. 1,75 and 6. 'I is ring can be readily slipped into place atthe flat faces 5 of the learner-body. rI`he underreamer or tool is then in condition to To accomplishbe lowered into the well. As the underreamerpasses into the casing, the ring 41 impinges the upper end of the casing and is released 'from engagement with the resilient arms 37. These arms are now held by the casing, and the ring 41 is removed, and the tool is further lowered. The tool can now be lowered into the casing and will pass through it without the dogs contacting with its interior. The enlargements 40 of theresilient arms havegtheir ends rounded so as to enter the casing readily and pass any slight obstructions it may meet as the tool is lowered through the casing. These roundf ed ends also permit of the tool being easily drawn upward through the casing. As the underreamer is lowered, the dogs, through the action of the interior walls of the casing holding the resilient arms from outwardV movement and thus holding the rod 9 from upwardl movement, will be held out of contact with the casing, avoiding wear on the dogs and injury to the casing. As soon as the enlargements 40 of the resilient arms pass below the lower end of the casing, which is elevated a short distance from the shoulder oftheY small hole to be reamed, these resilient arms will be forced upwardly in the recesses 35 by virtue of the spreader head 8 moving upwardly between the dogs, caused by the expansion of the springs 11 and 12. The dogs are then expanded or in position for' operation, as illustrated in Fig. 2 of' the of the dogs occupy approximately the area- 'ot the endk of the reamer-body, consequently these dogs will be lprevented from collapsing, and in action will be as durable as if they were formed integral with the reamerbody. This is an important feature of my invention and insures stability of the dogs. As the underreamer or tool is raised ,and allowed to fall, as in the usual operation of reaming the hole of a well, the lower outer edges 23 of the dogs will strike upon the shoulder left below the lower end of the casing and cut it awa-y, thus enlarging or reaming out the hole previously drilled to the size desired. In raising and lowering the underreamer, the force of impact drives the dogs downwardly, this torce being sustained by the reamer-body 1, which provides a substantial backing and prevents the force of4 impact beingiin any other lines than vertical. As the hole is reamed, the casing can be lowered. .In withdrawing the underreamer, the upward movement of the same, causes the enlargements 40 of thel resilient arms or trip bars 37 to im inge the lower end of the casing, holding t e arms or bars 37, thel spreader head 8 and the rod 9, while the upward -movement of the reamer-body places ,the springs 11 and 12` .undertensiou This movement of the underreamer contracts or draws the do s inwardly, and immediately v upon the shou ders 36 of the recesses 35 registering with the upper endsof the arms. or bars 37, these arms recede, enter -the casing and are held against the shoulders 36 by the interior wall of the casing. The tool then can be completely withdrawn from the casing.

strong and durable material, such as steel,

and on account of the compact arrangement ings, .particularly by those skilled in hanv ried by the lower'end of sai spreader head the tongues ycarrie dling underreamers.

I reserve the right-to make such changes the size, ro ortion and minor details as are permissi le y the appended claims.

Having now described my invention what I claim as new, is

1; In an underreamer, the combination with a spring-case, of a reamer-body carried thereby and having a bore formed therein,

Vsaid reamer-body having its lower end provided fwith diametrically o posed dove-tail grooves, dogs, tongues carrled by said dogs and adapted to tin said grooves, tongues carried by the confronting faces 'of said dogs, a spring held rod mounted in the bore of said reamer-body and extending into said spring-case, a spreader head secured to'the lower end of said rod andhaving grooves formed therein to receive the tongues of said dogs, a resilient platev sprin or strip carand adapted to im inge the lowerends of by said dogs, and resilient arms or tri vbarsloosel connected to -said spreader hea and-exten ing u wardly in the sides of said reamer-body or temporarily holding said spreader head in a` lowered positiony durin the passage of said underreamer through t e` casing.' y

2. In an underreamer, the combination of a reamer-body having diametrically-o posed recesses formed therein, with op osite y dislposed* grooves at its lowerend, o s mounted fr lateral movement `in sai grooves, ton ues carried by the confrontingfaces 'of sai do s, a spring held rod mounted in said .reamerf ody, a s reader head `fixed upon the lower end of sai rod, and having grooves to The underreamer in its entiretyis made ofv receive the tonguesof said dogs, a resilient v'strip carried by the lower end of said head for lmpinging the lower ends of thetongues of sai dogs, 'and meansjfor temporarily holding said spreader head'iri a'loweredl position during the passage of a tool throughv the casing. 3. In an underreamer, the comblnation of a reamer-body having its lower end prol-v vided with diametrically opposed dove-tail.

grooves, dogs movably mounted in said rooves, tongues carried by the confronting aces ofsaid dogs, a spring pressed .rod supe ported by said reamerbody,.a spreader headl carried by the llower end of saidrod and having grooves formed therein-to receive the tongues of saidl dog, and means carried by f said spreader head and engaging diametrlcally opposed sides `of said reamer-bodyfor holding said dogs out of engagement with a casing when therethrough.

4. In an underreamer, the combination of a reamer-body, laterally movable confr0nting dogs arranged at thelower end ofv said f i body, a spring pressed rod supported by said body, a spreader head carried by the`vlower.

end of said lrod and sli'dably connected to said 'dogs for expanding and retracting thel said s reader same, and means carried 'b n head and engaging in the siy es of sald body for holding said dogs in a retracted lposition through a casing.

. 5. In an underreamer, the combination of -a reamer-body, diametrically opposed movable dogs connected to the lower end there,

of, a spreader head movably supported from said reamer-body and slidably connected to 4said dogs for expandin and retractin fthe same, means carried by t e lower end o said head for firmly holding said dogs in engagevment with said reamerbod'y,and meanscar' ried by said head andengag'lng said reamerbody for normally holding sai dogs in a retracted position during. the passage of the .underreamer through a casing.

6. In an underreamer, the combination of.-

a reamer-body, laterally movable dogs carried thereby, a spring sup orted spreader head arranged between said) dogs Aand slidf ablyconnected thereto forexpanding and retracting said .-dogs, and means for holding said dogs in a retracted position during the '95 during the passage of said underreamer' passage of said underreamer through a cas# 1n In an' underreamer, the combination of al'reamer-body, laterally movable' dogs connected thereto, a spreader head Supported by said reamer-body for moving vertically b ev tween saiddogs and expanding and retract-z ing the same, means carried by the lower end of said lspreader head for firmly holding said dogs in engagement with sald reamerbody, and means carried by said head for normally holding said dogs in a retracted position during the passage of said tool through a casing.

8. An underreamer comprising a reamerbody rovided in its lower end with a (groove, latera y-movable o positely-dispose dogs movable horizonta in said groove, a'

spreader-head mova le vertically between spreader-head or engagement with the ower ends of the dogs when thelatter are in an extended position to hold said dogs a ainst vertical movement independently 4o reamer-body'.

9. An underreamer comprising a reamerbody, laterally movable dogs connected thereto, said dogs movable horizontall towards and away from the. axis of sai body, a spreader-head supported -by said bodyand Y movable vertically between said dogs, means carried by said s reader-head and engaging said spreader-bo y for holding said headin alowered position during the passage of the 'underreamer throu h a casing, and resilient y*means carried by t e spreader-head for engagement with the dogs when the latter are j ln' an .extended positionto hold-them a ainst Vvertical movement independently o Y 'the' I spreader-bod A 10. Anun erreamer comprising a reamerbody, a pair o'reamer-bits having atongue and oove `connection with Ythe lower end 'of v saidA od a spreader-head having a tongue 4.0

and groove connection with said reamerbits, said spreader-head movable vertically between the rea'mer-bitsv to extend and retract the same, and means carried by said spreader-head Vfor engagement withY the 4-5` reamer-bits whenthe atter arein an extended position to hold the same against vertical movement at their tongue and groove connection with'the reamer-body.

1l. An underreamer comprising a reamer. body, Vdogs vslidably-connected to the lower end thereof to 'move in a horizontal vline towardsA and away from the axis of said body, means supported by saidreamer-body for expanding and reti-acting said dogs, and

the

' means for holding said dogs ina retracted position during the` passage of the tool through a casing.

'12.. In an underreamer, the combination of a reamer-body, reamer-bits carried thereby and having a sliding connection with the body whereby they may be moved towards and away fromthe-axis of said body, means operating between said reamer-bits and connected therewith for extending and retract- `ing thebits, and -resilientmeans carried by `thesaid first-named means for engagement withthe reamer-bits when the latter are extended to force said reamer-bits towards the reamer-body and prevent lost motion at the point where said bits are connected to said body.

13. In an underreamer, a reamer-body,

reamer-bits vhaving a tongue and groove connection withsaid body and-movable later- Vally in a horizontal line towards and away from the axis of said body, the said body having a recess at its lower end, a spreaderblock movable vertically between the reamer- .bits toV extend and retract the latter, said spreader-block in the extended position of the bits-projecting into the recess in said body, and ai spring-plate carried by the lower end of the spreader-head for engagement with the lower ends of the reamer-bits when the latter arein an extended position to prevent lost motion between the bits and .thereamer-body at the point where said bits are connected' to said reamer-body.

14. An underream'er comprising a reamervbody, reamer-bits slidably connected to the lowerend thereof to move in a horizontal line towards and away from the axis of Vsaid body, means supported by said reamer body for extendin and retracting said reamerbits, means or holding -said reamer-bits in retracted position during the vpassage of `the underreamerthrough a casing and a spring plate carried by the first-named means for engagement withl the reamer-bits when the latterare in an extended. position for forcing the reamer-bits towards the reamer-body,

as and for the purpose described.A

In testimony whereof I aix mysignature in thefpresence of two'witnesses.

' CLARENCE T, MAPES. Y Witnesses: i

H. SnoLovrrz, K. H. BUTLER. 

